The present invention relates to a fireplace heating unit and more particularly, the invention is directed to a pair or series of isolated and parallel, spatially connected hollow tubing structures having heat exchange air paths with at least three or more zigzag direction reversal paths and in which a single blower supplies air to both tubing structures from a lower air space or outside air which may be mixed with air from the air space surrounding the fireplace with heated air being discharged through two separate outlets in the space being heated.